[llvm] llvm-reduce: Trim includes in ReduceInstructions (PR #135022)

[Matt Arsenault via llvm-commits]

arsenm wrote:

### Merge activity

* **Apr 9, 3:13 PM EDT**: A user started a stack merge that includes this pull request via [Graphite](https://app.graphite.dev/github/pr/llvm/llvm-project/135022).


https://github.com/llvm/llvm-project/pull/135022